Stepped mandrel



FIG. 1 is an isometric view;

FIG. 2 is a side view;

FIG. 3 is a perspective view;

FIG. 4 is a front view; and,

FIG. 5 is a back view.

The broken lines in the drawings depict unclaimed environmental subject matter. 

The ornamental design for a stepped mandrel, as shown and described. 